We outline the rationale and preliminary results of using the State Context Property (SCOP) formalism, originally developed as a generalization of quantum mechanics, to describe the contextual manner in which concepts are evoked, used, and combined to generate meaning. The quantum formalism was developed to cope with problems arising in the description of (1) the measurement process, and (2) the generation of new states with new properties when particles become entangled. Similar problems arising with concepts motivated the formal treatment introduced (...) here. Concepts are viewed not as fixed representations, but entities existing in states of potentiality that require interaction with a context---a stimulus or another concept---to `collapse' to observable form as an exemplar, prototype, or other (possibly imaginary) instance. The stimulus situation plays the role of the measurement in physics, acting as context that induces a change of the cognitive state from superposition state to collapsed state. The collapsed state is more likely to consist of a conjunction of concepts for associative than analytic thought because more stimulus or concept properties take part in the collapse. We provide two contextual measures of conceptual distance---one using collapse probabilities and the other weighted properties---and show how they can be applied to conjunctions using the pet fish problem. (shrink)

In this essay, I connect the sexual victimization of women, children, and pet animals with the violence manifest in a patriarchal culture. After discussing these connections, I demonstrate the importance of taking seriously these connections because of their implications for conceptual analysis, epistemology, and political, environmental, and applied philosophy. My goal is to broaden our understanding of issues relevant to creating peace and to provide some suggestions about what must be included in any adequate feminist peace politics.

Elizabeth Anderson’s “pluralist–expressivist” value theory, an alternative to the understanding of value and rationality underlying the “rational actor” model of human behavior, provides rich resources for addressing questions of environmental and animal ethics. It is particularly well-suited to help us think about the ethics of commodification, as I demonstrate in this critique of the pet trade. I argue that Anderson’s approach identifies the proper grounds for criticizing the commodification of animals, and directs our attention to the importance of maintaining social (...) practices and institutions that respect the social meanings of animals. Her theory alone, however, does not adequately address the role of the state in this project. Drawing on social contract theory to fill this gap, I conclude that the state’s role in regulating the pet trade should be limited to ensuring the welfare of animals in the stream of commerce, not prohibiting their mass marketing altogether. (shrink)

In the past twenty years Pet Facilitated Therapy has been used, apparently successfully, with several populations, including nursing home residents. Studies report positive behavior changes as a result of PFT intervention, but little effort has been made to quantify such behavior changes. This study presents the results of a PFT program in a nursing home setting. Results were positive, and were measured using the Patient Social Behavior Scale, designed for this study. Nursing home residents showed an increase of social behaviors (...) from pretest to midpoint and from midpoint to post test, but these behaviors declined four weeks after post test. Although both males and females showed an increase in social behaviors, males' and females' response patterns differed. (shrink)

A pilot study examined the relationship in daily life between companion animal guardianship and peoples' laughter. The study divided participants into 4 mutually exclusive groups: dog owners, cat owners, people who owned both dogs and cats, and people who owned neither. For one day, participants recorded in "laughter" logs the frequency and source of their laughter and the presence of others when laughing. Dog owners and people who owned both dogs and cats reported laughing more frequently than cat owners, as (...) did people who owned neither. The most frequent source of laughter was spontaneous laughter resulting from a situation. People who owned both dogs and cats reported most frequent spontaneous laughter resulting from an incident involving a pet. Dog owners reported less; cat owners, the least. Dog owners and people who owned both dogs and cats reported laughing more frequently in the presence of their pets than did cat owners. Findings suggest a complex relationship between pet ownership and laughter. Dogs may serve as friends with whom to laugh or their behaviors may provide a greater source of laughter. (shrink)

Speech production involves the generation of an auditory signal from the articulators and vocal tract. When the intended auditory signal does not match the produced sounds, subsequent articulatory commands can be adjusted to reduce the difference between the intended and produced sounds. This requires an internal model of the intended speech output that can be compared to the produced speech. The aim of this functional imaging study was to identify brain activation related to the internal model of speech production after (...) activation related to vocalisation, auditory feedback and movement in the articulators had been controlled. There were four conditions: silent articulation of speech, non-speech mouth movements, finger tapping and visual fixation. In the speech conditions, participants produced the mouth movements associated with the words “one” and “three”. We eliminated auditory feedback from the spoken output by instructing participants to articulate these words without producing any sound. The non-speech mouth movement conditions involved lip pursing and tongue protrusions to control for movement in the articulators. The main difference between our speech and non-speech mouth movement conditions is that prior experience producing speech sounds leads to the automatic and covert generation of auditory and phonological associations that may play a role in predicting auditory feedback. We found that, relative to non-speech mouth movements, silent speech activated Broca's area in the left dorsal pars opercularis and Wernicke's area in the left posterior superior temporal sulcus. We discuss these results in the context of a generative model of speech production and propose that Broca’s and Wernicke’s areas may be involved in predicting the speech output that follows articulation. These predictions could provide a mechanism by which rapid movement of the articulators is precisely matched to the intended speech outputs during future articulations. (shrink)

Pet animal management is subject to varied husbandry practices and the resulting consequences often impact negatively on animal welfare. The perceptions held by someone who proposes to keep an animal regarding the ease or difficulty with which its biological needs can be provided for in captivity are key factors in whether that animal is acquired and how well or poorly it does. We propose a system to ‘score’ animals and assign them to categories indicating the ease or difficulty with which (...) they can be kept as pets in accordance with welfare and public health and safety considerations. The ‘EMODE’ (‘Easy’, ‘Moderate’, ‘Difficult’, ‘Extreme’) system has two fundamental components: animal welfare—which considers the ‘five freedoms’ principles; and public health and safety—which considers management associated with risks from disease or injury to the keeper and to others. EMODE incorporates two tiers of assessment and guidance, and may offer a reasonable guide for the majority of relevant animals. EMODE Tier 1 provides a primary and general assessment of animals by class or group, and EMODE Tier 2 provides a secondary refined assessment of animals by species or breed. EMODE offers a user-friendly and versatile foundation concept for the future development of guidance for the layperson who may be considering acquiring a pet or for certain personnel when considering assigning species to restrictive lists of suitable animals, for example, ‘positive lists’ as used by governments to control animals in trade and keeping. (shrink)

Stiff Person Syndrome (SPS) is a rare autoimmune disorder associated with antibodies against glutamic acid decarboxylase (GAD-Ab), the key enzyme in γ -aminobutyric acid synthesis (GABA). In order to investigate the role of cerebral benzodiazepinereceptor binding in SPS, we performed [ 11 C]flumazenil (FMZ) positron emission tomography (PET) in a female patient with SPS compared to nine healthy controls. FMZ is a radioligand to the postsynaptic central (...) benzodiazepine receptor which is co-localized with the GABA-A receptor. In the SPS patient, we found a global reduction of cortical FMZ binding. In addition, distinct local clusters of reduced radiotracer binding were observed. These data provide first in vivo evidence for a reduced postsynaptic GABA-A receptor availability which may reflect the loss of GABAergic neuronal inhibition in SPS. (shrink)

Although it is widely accepted that nouns and verbs are functionally independent linguistic entities, it is less clear whether their processing recruits different brain areas. This issue is particularly relevant for those theories of lexical semantics (and, more in general, of cognition) that suggest the embodiment of abstract concepts, i.e., based strongly on perceptual and motoric representations. This paper presents a formal meta‑analysis of the neuroimaging evidence on noun and verb processing in order to address this dichotomy more effectively at (...) the anatomical level. We used a hierarchical clustering algorithm that grouped fMRI/PET activation peaks solely on the basis of spatial proximity. Cluster specificity for grammatical class was then tested on the basis of the noun‑verb distribution of the activation peaks included in each cluster. 32 clusters were identified: three were associated with nouns across different tasks (in the right inferior temporal gyrus, the left angular gyrus, and the left inferior parietal gyrus); one with verbs across different tasks (in the posterior part of the right middle temporal gyrus); and three showed verb specificity in some tasks and noun specificity in others (in the left and right inferior frontal gyrus and the left insula). These results do not support the popular tenets that verb processing is predominantly based in the left frontal cortex and noun processing relies specifically on temporal regions; nor do they support the idea that verb lexical‑semantic representations are heavily based on embodied motoric information. Our findings suggest instead that the cerebral circuits deputed to noun and verb processing lie in close spatial proximity in a wide network including frontal, parietal, and temporal regions. The data also indicate a predominant – but not exclusive – left lateralization of the network. (shrink)

The status of wild capture fisheries has induced many fisheries and conservation scientists to express concerns about the concept of using forage fish after reduction to fishmeal and fish oil, as feed for farmed animals, particularly in aquaculture. However, a very large quantity of forage fish is being also used untransformed (fresh or frozen) globally for other purposes, such as the pet food industry. So far, no attempts have been made to estimate this quantum, and have been omitted in previous (...) fishmeal and fish oil exploitation surveys. On the basis of recently released data on the Australian importation of fresh or frozen fish for the canned cat food industry, here we show that the estimated amount of raw fishery products directly utilized by the cat food industry equates to 2.48 million metric tonnes per year. This estimate, plus the previously reported global fishmeal consumption for the production of dry pet food suggest that 13.5% of the total 39.0 million tonnes of wild caught forage fish is used for purposes other than human food production. This study attempts to bring forth information on the direct use of fresh or frozen forage fish in the pet food sector that appears to have received little attention to this date and that needs to be considered in the global debate on the ethical nature of current practices on the use of forage fish, a limited biological resource. (shrink)

Auditory verbal hallucinations (AVH) or ‘voices’ are a characteristic symptom of schizophrenia, but can also be observed in healthy individuals in the general population. As these non-psychotic individuals experience AVH in the absence of other psychiatric symptoms and medication-use they provide an excellent model to study AVH in isolation. Indeed a number of studies used this approach and investigated brain structure and function in non-psychotic individuals with AVH. These studies showed that aberrant connectivity of language production and perception areas is (...) particularly associated with AVH. This is in concordance with investigations that observed prominent activation of these language areas during the state of AVH. Effortful attention decreased cerebral dominance for language and dopamine dysfunction on the other hand, are presumably not specifically related to AVH. (shrink)

Although positron emission tomography (PET) and the aromatic L-amino acid decarboxylase (AADC) tracer 6-[18F]fluoro-L-m-tyrosine (FMT) has been used to assess the integrity of the presynaptic dopamine system in the brain, relatively little has been published in terms of brain FMT uptake values especially for normal human subjects. Twelve normal volunteer subjects were scanned using PET and FMT to determine the range of normal striatal uptake values using Patlak graphical analysis. For comparison, seven adult rhesus monkeys were studied and the data (...) analyzed in the same way. A subset of monkeys that were treated with a unilateral intracarotid artery infusion of the dopamine neurotoxin MPTP showed an 87% decrease in striatal FMT uptake. These findings support the use of PET and FMT to image AADC distribution in both normal and diseased brains using Patlak graphical analysis and tissue input functions. (shrink)

The antisaccade task is a classic task of oculomotor control that requires participants to inhibit a saccade to a target and instead make a voluntary saccade to the mirror opposite location. By comparison, the prosaccade task requires participants to make a visually-guided saccade to the target. These tasks have been studied extensively using behavioural oculomotor, electrophysiological and neuroimaging in both non-human primates and humans. In humans, the antisaccade task is under active investigation as a potential endophenotype or biomarker for multiple (...) psychiatric and neurological disorders. A large and growing body of literature has used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) to study the neural correlates of the antisaccade and prosaccade tasks. We present a quantitative meta-analysis of all published voxel-wise fMRI and PET studies (18) of the antisaccade task and show that consistent activation for antisaccades and prosaccades is obtained in a fronto-subcortical-parietal network encompassing frontal and supplementary eye fields, thalamus, striatum and intraparietal cortex. This network is strongly linked to oculomotor control and was activated to a greater extent for antisaccade than prosaccade trials. Antisaccade but not prosaccade trials additionally activated dorsolateral and ventrolateral prefrontal cortices. We also found that a number of additional regions not classically linked to oculomotor control were activated to a greater extent for antisaccade versus prosaccade trials; these regions are often reported in antisaccade studies but rarely commented upon. While the number of studies eligible to be included in this meta-analysis was small, the results of this systematic review reveal that antisaccade and prosaccade trials consistently activate a distributed network of regions both within and outside the classic definition of the oculomotor network. (shrink)

This paper offers a framework for consciousness of internal reality. Recent PET experiments are reviewed, showing partial overlap of cortical activation during self-produced actions and actions observed from other people. This overlap suggests that representations for actions may be shared by several individuals, a situation which creates a potential problem for correctly attributing an action to its agent. The neural conditions for correct agency judgments are thus assigned a key role in self/other distinction and self-consciousness. A series of behavioral experiments (...) that demonstrate, in normal subjects, the poor monitoring of action-related signals and the difficulty in recognizing self-produced actions are described. In patients presenting delusions, this difficulty dramatically increases and actions become systematically misattributed. These results point to schizophrenia and related disorders as a paradigmatic alteration of a ''Who?'' system for self-consciousness. (shrink)

I explore how some aspects of Foucoult’s work on power can be applied to human/animal power relations. First, I argue that because animals behave as “beings that react” and can respond in different ways to human actions, in principle at least, Foucoult’s work can offer insights into human/animal power relations. However, many of these relations fall into the category of “domination,” in which animals are unable to respond. Second, I examine different kinds of human power practices, in particular, ways in (...) which humans construct animal constitutions and animal subjectivities. Finally, I use a case study of a pet cat to show how such power practices may come together in a single instance. (shrink)

This article examines the neurobiological basis of the healing power attributed to shamanic practices in the Andes and Brazil in light of the pharmacology of neurotransmitters and the new technological explorations of brain functioning. The psychotropic plants used in shamanic psychiatric cures interfere selectively with the intrinsic neuromediators of the brain. Mainly they may alter: (1) the neuroendocrine functioning through the adrenergic system by controlling stressful conditions, (2) the dopaminergic system in incentive learning and emotions incorporation, (3) the serotoninergic system (...) in modulating behaviors, and mood, and (4) basic functions implied in anxiety or depression. PET scans and functional magnetic resonance imaging studies of hypnotic trance and altered states of consciousness may provide a useful model for the neurophysiological phenomena of shamanic drum-and-dance trance. The reorganization of cortical areas and the direct interconnections between the prefrontal cortex and the dopaminergic reward centers in the limbic system are of particular significance for human social judgment and symbolic processing. Those centers—including the hypothalamus and the amygdala (associated with psychosomatic equilibrium, memory, and emotion) are enhanced. This arousal may be amplified in order to induce a cathartic crisis—the shamanic trance. It is suggested that through this holistic approach the shaman empirically interferes in neurobiological dysfunctions. (shrink)

Recent innovations in computer software development have produced a new breed of pet, AIBO 2, a robotic pet that simulates the behavior of real pets. This paper argues that software developers who create such simulations have ethical responsibilities to product users and to society. The paper concludes with some general ethical guidelines for software developers to follow when engaged in projects involving real-world simulations.

The recent 'animal turn' in geography has contributed to a critical examination of the inseparable geographies of human and non-human animals, and has a clear ethical dimension. This paper is intended to explore these same ethical issues through a consideration of the historical geography of petkeeping as this relates to the death and commemoration of favourite household animals. The emergence of the pet cemetery, towards the end of the 19th century, is a significant step in itself, but this was only (...) one element in a radical reappraisal of the place of non-human animals in human sensibility and spirituality. For some bereaved pet-owners, the old question of the immortality of animal souls was retrieved and transformed, and sustained by a raft of unorthodox theological and spiritual speculation. The significance of this late Victorian and Edwardian response to non-human animals is assessed and treated as a problem of ethics, as a counterweight to the dominant anthropocentrism of past times and ours. (shrink)

It's a sort of moebus strip argument. Rather than circularly assuming what it should prove, it assumes one of the things Fodor says he has disproved. It assumes that the extensions of those concepts thought by some to be recognitional are in fact controlled by stereotypes. Why do I say that? Because Fodor assumes that what makes an instance of a concept a "good instance" is that it is an average instance, that it sports the properties statistically most commonly found (...) among instances of that concept. But that the "good instances" are always the common instances is remotely plausible only if we take concepts to be organized by stereotypes. True, a goldfish is not an average or stereotypical fish (SSis that true?) and the nursing profession is not average for a male and maleness is not average for a nurse. But there is surely is nothing borderline about the fishiness of a goldfish nor, typically, about the maleness of a male nurse or the petness of a pet fish. Notice also that good examples of some kinds of things are very hard to find, for example, good examples of the fallacy of accent, and good examples of wild children, and (nowadays) good examples of scurvy are hard to find. If good instances had to be instances that were average, including in respects having nothing to do with the point of the category being defined, and if recognitional concepts had to recognize by attending to average properties, then I suppose the recognitional ability defining the concept "sphere" would have to include the ability to tell whether a thing bounces! (shrink)

In this chapter, we aimed at further characterizing the functional neuroanatomy of the human rapid eye movement (REM) sleep at the population level. We carried out a meta-analysis of a large dataset of positron emission tomography (PET) scans acquired during wakefulness, slow wave sleep and REM sleep, and focused especially on the brain areas in which the activity diminishes during REM sleep. Results show that quiescent regions are conﬁned to the inferior and middle frontal cortex and to the inferior parietal (...) lobule. Providing a plausible explanation for some of the features of dream reports, these ﬁndings may help in reﬁning the concepts, which try to account for human cognition during REM sleep. In particular, we discuss the significance of these results to explain the alteration in executive processes, episodic memory retrieval and self representation during REM sleep dreaming as well as the incorporation of external stimuli into the dream narrative. (shrink)

The sets of contexts and properties of a concept are embedded in the complex Hilbert space of quantum mechanics. States are unit vectors or density operators, and contexts and properties are orthogonal projections. The way calculations are done in Hilbert space makes it possible to model how context influences the state of a concept. Moreover, a solution to the combination of concepts is proposed. Using the tensor product, a procedure for describing combined concepts is elaborated, providing a natural solution to (...) the pet fish problem. This procedure allows the modeling of an arbitrary number of combined concepts. By way of example, a model for a simple sentence containing a subject, a predicate and an object, is presented. (shrink)

Social learning and imitation is central to culture in cetaceans. The training technology used with cetaceans facilitates reinforcing imitation of one dolphin's behavior by another; the same technology, now widely used by pet owners, can lead to imitative learning in such unlikely species as dogs and horses. A capacity for imitation, and thus for cultural learning, may exist in many species.

The relation between mind and brain is one of the big scientific questions that has attracted scientists’ attention for centuries but also eluded their understanding. In this book, William Uttal provides a critical review of cognitive neuroscience, focusing on a specific question: What do the brain-imaging techniques developed in the last two decades or so—mostly functional magnetic resonance imaging and positron emission tomography —tell us about the brain-mind problem? His unambiguous and abrasive answer is: nothing.The book is organized in nine (...) chapters. The introductory chapter provides historical, methodological, and philosophical background. Importantly, it highlights a shift in the way neuroscientists think about modularity and localization. Traditionally, researchers using brain imaging have tended to subscribe to a strong view of modularity and localization, where distinct cognitive modules are assumed to be localized in well-defined regions of the brain. In the l .. (shrink)

When animals are trained to function in a human society (for example, pet dogs, police dogs, or sports horses), different trainers and training cultures vary widely in their ability to understand how the animal perceives the communication efforts of the trainer. This variation has considerable impact on the resulting performance and welfare of the animals. There are many trainers who frequently resort to physical punishment or other pain-inflicting methods when the attempts to communicate have failed or when the trainer is (...) unaware of the full range of the potential forms of human-animal communication. Negative consequences of this include animal suffering, imperfect performance of the animals, and sometimes risks to humans, as repeated pain increases aggression in some animals. The field of animal training is also interesting from a semiotic point of view, as it effectively illustrates the differences between the distinct forms of interaction that are included in the concept of communication in the zoosemiotic discourse. The distinctions with the largest potential in improving human-animal communication in animal training, is understanding the difference between verbal communication of the kind that requires rather high cognitive capabilities of theanimal, and communication based on conditioning, which is a form of animal learning that does not require high cognitive ability. The differences and potentials of various types of human-animal communication are discussed in the form of a case study of a novel project run by a NGO called Working Elephant Programme of Asia (WEPA), which introduces humane, science-based training and handling methods as an alternative to the widespread use of pain and fear that is the basis of most existing elephant training methods. (shrink)

Brindley proposed that we initially generate movements , under higher cerebral control. As the movement is practiced, the cerebellum learns to link within itself the context in which the movement is made to the lower level movement generators. Marr and Albus proposed that the linkage is established by a special input from the inferior olive, which plays upon an input-output element within the cerebellum during the period of the learning. When the linkage is complete, the occurrence of the context (represented (...) by a certain input to the cerebellum) will trigger (through the cerebellum) the appropriate motor response. The movement is distinguished from the conscious movement by its now being automatic, rapid, and stereotyped. The idea is still controversial, but has been supported by a variety of animal studies and, as reviewed here, is consistent with the results of a number of human PET and ablation studies. I have added to the idea of context-response linkage what I think is another important variable: novel combinations of downstream elements. With regard to the motor system and the muscles, this could explain how varied combinations of muscles may become active in precise time-amplitude specifications so as to produce coordinated movements appropriate to specific contexts. In this target article, I have further extended this idea to the premotor parts of the brain and their role in cognition. These areas receive influences from the cerebellum; they are active both in planning movements that are to be executed and in thinking about movements that are not to be executed. From recent evidence, the cerebellar output extends even to what has been characterized as the ultimate frontal planning area, the cortex, area 46. The cerebellum thus may be involved in context-response linkage, and response combination even at these higher levels. The implication would be that, through practice, an experiential context would automatically evoke a certain mental action plan. The plan would be in the realm of thought, and could lead to execution. The specific cerebellar contribution would be one of the context linkage and the shaping of the response, through trial and error learning. The prefrontal and premotor areas could still plan without the help of the cerebellum, but not so automatically, rapidly, stereotypically, so precisely linked to context, or so free of error. Nor would their activities improve optimally with mental practice. (shrink)

Depue & Collins's (D&C's) work relies on extrapolation from data obtained through studies in experimental animals, and needs support from studies of the role of dopamine (DA) neurotransmission in human behaviour. Here we review evidence from two sources: (1) studies of patients with Parkinson's disease and (2) positron emission tomography (PET) studies of DA neurotransmission, which we believe lend support to Depue & Collins's theory, and which can potentially form the basis for a true neurochemistry of personality.

This article considers the roles played by brain images (e.g., from PET scans) in mass media as experienced by people suffering from mental illness, and as used by scientists and activist groups in demonstrating a biological basis for mental illness. Examining the rhetorical presentation of images in magazines and books, the article describes the persuasive power that brain images have in altering the understanding people have of their own bodyâtheir objective self. Analyzing first-person accounts of encounters with brain images, it (...) argues that people come to understand themselves as having neurotransmitter imbalances that are the cause of their illnesses via received facts and images of the brain, but that this understanding is incomplete and in tension with the sense that they are their brain. The article concludes by querying the emergence of a pharmaceutical self, in which one experiences one's brain as if on drugs, as a new form of objective self-fashioning. (shrink)

The aim of the present study was to explore the cerebral substrates of episodic memory disorders in Alzheimer’s disease (AD) and investigate patients' hyperactivations frequently reported in the functional imaging literature. It remains unclear whether some of these hyperactivations reflect compensatory mechanisms or deactivation disturbances in the default mode network. Using positron emission tomography (15O-H2O), cerebral blood flow was measured in eleven ADs and twelve healthy elderly controls at rest and during encoding and stem-cued recall of verbal items. We performed (...) subtractions analyses between the experimental and control conditions between groups. The average signal was extracted in regions showing hyperactivation in AD patients versus controls in both contrasts. To determine whether hyperactivations occurred in regions that were activated or deactivated during the memory tasks, we compared signal intensities between the experimental conditions versus rest. Our results showed reduced activation in ADs compared to controls in several core episodic memory regions, including the medial temporal structures, during both encoding and retrieval. ADs also showed hyperactivations compared to controls in a set of brain areas. Further analyses conducted on the signal extracted in these areas indicated that most of these hyperactivations in ADs actually reflected a failure of deactivation. Indeed, almost all of these regions were significantly more activated at rest than during the experimental conditions in controls, only one region presented a similar pattern of deactivation in ADs. Altogether, our findings suggest that hyperactivations in AD must be interpreted with caution and may not systematically reflect compensatory mechanisms. Although there has been evidence supporting the existence of genuine compensatory mechanisms, dysfunction within the default mode network may be responsible for part of the apparent hyperactivations reported in the literature on AD. (shrink)

The aim of the present study was to explore the cerebral substrates of episodic memory disorders in Alzheimer’s disease (AD) and investigate patients' hyperactivations frequently reported in the functional imaging literature. It remains unclear whether some of these hyperactivations reflect compensatory mechanisms or deactivation disturbances in the default mode network. Using positron emission tomography (15O-H2O), cerebral blood flow was measured in eleven ADs and twelve healthy elderly controls at rest and during encoding and stem-cued recall of verbal items. We performed (...) subtractions analyses between the experimental and control conditions between groups. The average signal was extracted in regions showing hyperactivation in AD patients versus controls in both contrasts. To determine whether hyperactivations occurred in regions that were activated or deactivated during the memory tasks, we compared signal intensities between the experimental conditions versus rest. Our results showed reduced activation in ADs compared to controls in several core episodic memory regions, including the medial temporal structures, during both encoding and retrieval. ADs also showed hyperactivations compared to controls in a set of brain areas. Further analyses conducted on the signal extracted in these areas indicated that most of these hyperactivations in ADs actually reflected a failure of deactivation. Indeed, almost all of these regions were significantly more activated at rest than during the experimental conditions in controls, only one region presented a similar pattern of deactivation in ADs. Altogether, our findings suggest that hyperactivations in AD must be interpreted with caution and may not systematically reflect compensatory mechanisms. Although there has been evidence supporting the existence of genuine compensatory mechanisms, dysfunction within the default mode network may be responsible for part of the apparent hyperactivations reported in the literature on AD. (shrink)

We have several intuitive paradigms of defeating evidence. For example, let E be the fact that Ernie tells me that the notorious pet Precious is a bird. This supports the premise F, that Precious can fly. However, Orna gives me *opposing* evidence. She says that Precious (the same Precious) is a dog. Alternatively, defeating evidence might not oppose Ernie's testimony in that direct way. There might be other ways for it to weaken the support that Ernie's testimony gives me for (...) believing F, without the new evidence itself intuitively constituting reasons to believe one way or the other about Precious's flight ability. An example: <span class='Hi'>Ursula</span> tells me that Ernie has no idea what Precious's species is; he's just guessing. She may not herself want to or be in a position to weigh in about Precious's real species or flight ability. I call defeating evidence of this sort *undermining evidence. (shrink)

If the cortex is an associative memory, strongly connected cell assemblies will form when neurons in different cortical areas are frequently active at the same time. The cortical distributions of these assemblies must be a consequence of where in the cortex correlated neuronal activity occurred during learning. An assembly can be considered a functional unit exhibiting activity states such as full activation (“ignition”) after appropriate sensory stimulation (possibly related to perception) and continuous reverberation of excitation within the assembly (a putative (...) memory process). This has implications for cortical topographies and activity dynamics of cell assemblies forming during language acquisition, in particular for those representing words. Cortical topographies of assemblies should be related to aspects of the meaning of the words they represent, and physiological signs of cell assembly ignition should be followed by possible indicators of reverberation. The following postulates are discussed in detail: (1) assemblies representing phonological word forms are strongly lateralized and distributed over perisylvian cortices; (2) assemblies representing highly abstract words such as grammatical function words are also strongly lateralized and restricted to these perisylvian regions; (3) assemblies representing concrete content words include additional neurons in both hemispheres; (4) assemblies representing words referring to visual stimuli include neurons in visual cortices; and (5) assemblies representing words referring to actions include neurons in motor cortices. Two main sources of evidence are used to evaluate these proposals: (a) imaging studies focusing on localizing word processing in the brain, based on stimulus-triggered event-related potentials (ERPs), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI), and (b) studies of the temporal dynamics of fast activity changes in the brain, as revealed by high-frequency responses recorded in the electroencephalogram (EEG) and magnetoencephalogram (MEG). These data provide evidence for processing differences between words and matched meaningless pseudowords, and between word classes, such as concrete content and abstract function words, and words evoking visual or motor associations. There is evidence for early word class-specific spreading of neuronal activity and for equally specific high-frequency responses occurring later. These results support a neurobiological model of language in the Hebbian tradition. Competing large-scale neuronal theories of language are discussed in light of the data summarized. Neurobiological perspectives on the problem of serial order of words in syntactic strings are considered in closing. Key Words: associative learning; cell assembly; cognition; cortex; ERP; EEG; fMRI; language; lexicon; MEG; PET; word category. (shrink)

Deep brain stimulation to different sites allows interfering with dysfunctional network function implicated in major depression. Because a prominent clinical feature of depression is anhedonia--the inability to experience pleasure from previously pleasurable activities--and because there is clear evidence of dysfunctions of the reward system in depression, DBS to the nucleus accumbens might offer a new possibility to target depressive symptomatology in otherwise treatment-resistant depression. Three patients suffering from extremely resistant forms of depression, who did not respond to pharmacotherapy, psychotherapy, and (...) electroconvulsive therapy, were implanted with bilateral DBS electrodes in the nucleus accumbens. Stimulation parameters were modified in a double-blind manner, and clinical ratings were assessed at each modification. Additionally, brain metabolism was assessed 1 week before and 1 week after stimulation onset. Clinical ratings improved in all three patients when the stimulator was on, and worsened in all three patients when the stimulator was turned off. Effects were observable immediately, and no side effects occurred in any of the patients. Using FDG-PET, significant changes in brain metabolism as a function of the stimulation in fronto-striatal networks were observed. No unwanted effects of DBS other than those directly related to the surgical procedure were observed. Dysfunctions of the reward system--in which the nucleus accumbens is a key structure--are implicated in the neurobiology of major depression and might be responsible for impaired reward processing, as evidenced by the symptom of anhedonia. These preliminary findings suggest that DBS to the nucleus accumbens might be a hypothesis-guided approach for refractory major depression. (shrink)

Within the field of medical ethics, discussions related to public health have mainly concentrated on issues that are closely tied to research and practice involving technologies and professional services, including vaccination, screening, and insurance coverage. Broader determinants of population health have received less attention, although this situation is rapidly changing. Against this backdrop, our specific contribution to the literature on ethics and law vis-à-vis promoting population health is to open up the ubiquitous presence of pets within cities and towns for (...) further discussion. An expanding body of research suggests that pet animals are deeply relevant to people’s health (negatively and positively). Pet bylaws adopted by town and city councils have largely escaped notice, yet they are meaningful to consider in relation to everyday practices, social norms, and cultural values, and thus in relation to population health. Nevertheless, not least because they pivot on defining pets as private property belonging to individual people, pet bylaws raise emotionally charged ethical issues that have yet to be tackled in any of the health research on pet ownership. The literature in moral philosophy on animals is vast, and we do not claim to advance this field here. Rather, we pragmatically seek to reconcile philosophical objections to pet ownership with both animal welfare and public health. In doing so, we foreground theorizations of personhood and property from sociocultural anthropology. (shrink)

We have previously shown that some blind individuals can localize sounds more accurately than their sighted counterparts when one ear is obstructed, and that this ability is strongly associated with occipital cortex activity. Given that spectral cues are important for monaural localizing sounds when one ear is obstructed, and that blind individuals are more sensitive to small spectral differences, we hypothesized that enhanced use of spectral cues via occipital cortex mechanisms could explain the better performance of blind individuals in monaural (...) localization. Using PET, we scanned blind and sighted persons as they discriminated between sounds originating from a single spatial position, but with different spectral profiles that simulated different spatial positions based on head-related transfer functions. We show here that a sub-group of early-blind individuals showing superior monaural sound localization abilities performed significantly better than any other group on this spectral discrimination task. For all groups, performance was best for stimuli simulating peripheral positions, consistent with the notion that spectral cues are more helpful for discriminating peripheral sources. PET results showed that all blind groups showed cerebral blood flow increases in the occipital cortex; but this was also the case in the sighted group. A voxel-wise covariation analysis showed that more occipital recruitment was associated with better performance across all blind subjects but not the sighted. Inter-regional covariation analysis showed that the occipital activity in the blind covaried with that of several frontal and parietal regions known for their role in auditory spatial processing. Overall, these results support the notion that the superior ability of a sub-group of early blind individuals to localize sounds is mediated by their superior ability to use spectral cues, and that this ability is subserved by cortical processing in the occipital cortex. (shrink)

Neural organization: Structure, function, and dynamics shows how theory and experiment can supplement each other in an integrated, evolving account of the brain's structure, function, and dynamics. (1) Structure: Studies of brain function and dynamics build on and contribute to an understanding of many brain regions, the neural circuits that constitute them, and their spatial relations. We emphasize Szentágothai's modular architectonics principle, but also stress the importance of the microcomplexes of cerebellar circuitry and the lamellae of hippocampus. (2) Function: Control (...) of eye movements, reaching and grasping, cognitive maps, and the roles of vision receive a functional decomposition in terms of schemas. Hypotheses as to how each schema is implemented through the interaction of specific brain regions provide the basis for modeling the overall function by neural networks constrained by neural data. Synthetic PET integrates modeling of primate circuitry with data from human brain imaging. (3) Dynamics: Dynamic system theory analyzes spatiotemporal neural phenomena, such as oscillatory and chaotic activity in both single neurons and (often synchronized) neural networks, the self-organizing development and plasticity of ordered neural structures, and learning and memory phenomena associated with synaptic modification. Rhythm generation involves multiple levels of analysis, from intrinsic cellular processes to loops involving multiple brain regions. A variety of rhythms are related to memory functions. The Précis presents a multifaceted case study of the hippocampus. We conclude with the claim that language and other cognitive processes can be fruitfully studied within the framework of neural organization that the authors have charted with John Szentágothai. Key Words: cognitive maps; computational neuroscience; dynamics; hippocampus; memory; modular architectonics; neural modeling; neural organization; neural plasticity; rhythmogenesis; Szentágothai. (shrink)

Computer ethics, or more broadly, Information Technology (IT) ethics, is often concerned with issues about privacy, accuracy, property and accessibility and framing of policies and rules on the features. While ethical issues on these topics are important, issues about IT ethics apply more broadly. The purpose of ethics is not just to draft new policies or legal codes. Ethics also aims to probe and bring into limelight for ethical deliberations those issues, which have escaped policy formulations or human introspection. This (...) paper tries to address one such ethical issue. This paper concerns with email ethics and with one of the features of emailing - ‘forwarding’. As an applied ethics domain, I have tried to use some samples of forwarded mails. Through the analysis of the given sample mails, I claim that (1) this issue of ‘forwarding’ falls well outside the domain of framing ethical policies and (2) it is a matter of ethical concern. I have addressed this ethical concern by drawing a criterion to judge if one’s act of ‘forwarding’ a mail is ethical act or not. (shrink)